@article {SAHU:2024:0736-2935:8180,
title = "Investigating the acoustic performance of metamaterials with internal simple expansion chamber structure",
journal = "INTER-NOISE and NOISE-CON Congress and Conference Proceedings",
parent_itemid = "infobike://ince/incecp",
publishercode ="ince",
year = "2024",
volume = "270",
number = "3",
publication date ="2024-10-04T00:00:00",
pages = "8180-8190",
itemtype = "ARTICLE",
issn = "0736-2935",
url = "https://ince.publisher.ingentaconnect.com/content/ince/incecp/2024/00000270/00000003/art00021",
doi = "doi:10.3397/IN_2024_4056",
author = "SAHU, Nihar Ranjan and MANDAL, Bibhuti Bhusan",
abstract = "The tunable acoustic properties are possessed by acoustic metamaterials (AMMs) with internal configurable structures. Nine samples(B1-B9) were designed in SOLIDWORKS and then fabricated using 3D-printed photopolymer resin featuring an internal Simple Expansion Chamber (SEC) structure.
SEC length varied from 2 to 18 mm, maintaining a constant area expansion ratio (m) of 16. Sound Absorption Coefficient (SAC) and Sound Transmission Loss (STL) were measured through the Impedance Tube Apparatus (ITA). The sample with a 4 mm SEC length exhibited a maximum SAC of 0.99 at 4.8
kHz. As SEC length increased peak SAC and peak absorption frequency linearly decreased. Across all samples, STL ranged from 1- 41 dB (0.5-2.4 kHz) and 20-36 dB (2.4-6 kHz) revealing a periodic pattern in the tested frequency range. With SEC increasing from 2 to 18 mm Peak STL decreased from
41.2 to 38.8 dB. This research contributes valuable insights into the design of acoustic materials for effective noise attenuation showcasing the potential for achieving at least a 20 dB reduction in the 2.4-6 kHz range.",
}